Butt contact mounting for rotary switches



1948- H. E. SCHLEICHER 2,453,161

BUTT CONTACT MOUNTING FOR ROTARY SWITCHES Filed July 28. 1945 2 Sheets-Sheet 1 1 161-0 I JM/ader 9/213 (O/Z1703?! Nov. 9 1948; T H. SCHLEICIHER 2,453,161

BUTT CONTACT MOUNTING FOR ROTARY SWITCTIES Filed July 28, 1945 I 2 Sheets-Sheet 2 Patented Nov. 9, 1948 FFHE BUTT CONTACT MOUNTING FOR ROTARY SWITCHES Harold E. Schleicher, West Hartford, Conn, as-

signor to The Arrow-Hart & Hegeman Eiectric 00., Hartford, Conn, a corporation of Connecticut Original application November 26, 1943, Serial No. 511,855. Divided and this application duly 28, 1945, Serial No. 607,555

'16 Claims.

fore to meet the test requirements involved the addition-of counterweights, inertia hammers, special brush-type contacts, etc, to existing conventional commercial structures. These have proved unsatisfactory under the new requirements. 'A new approach to the problem was needed to produce a scientifically designed device in which the movable parts would be dynamically and statically balanced.

It is an object of the present invention to provide contact structure for an electromagneticallyoperated circuit maker and breaker, said contact structure being constructedon like principles to the operating mechanism of the breakerto withstand high impact tests by providing for dynamic and static balance of its moving parts. A related object is to provide an improved construction and mounting of butt type contact structure for use in rotary electric switches and circuit breakers generally, but particularly useful in balanced electromagnetically-operated rotary switches. Another object is to provide a butt type bridging contact structure for rotary switches which will maintain a firm and consistent pressure against the fixed contacts, and, concomitantly to provide a mounting for said bridging contact which, despite possible manufacturing inaccuracies, will enable the bridging contact to adjust itself to the fixed contacts for firm engagement therewith.

Another object is to provide a bridging contact of the foregoing self-adjusting type, of which several may be mounted on a common shaft for movement together to engage diiferent sets of fixed contacts whose positions may vary due to manufacturing tolerances and inaccuracies, and all of which will properly engage their complementary fixed contacts.

Another object is to provide for maintaining the circuit closed in case of momentary disengagement of the butt contact elements. A related object is to provide means to cause the circuit maintaining contacts to come into engagement after the butt contacts became engaged and to disengage before the butt contacts separated.

Another object is to provide for a resilient mounting and engagement of the contacts in a butt type contact structure for use under the aforesaid conditions and to provide for positive movement to cause contact engagement and disengagement.

Other objects and advantages will become apparent as the invention is described in connection with the drawings.

In the drawings- Fig. 1 is a perspective view of a device embodying the invention;

Fig 2 is a perspective view of one section of the device illustrated in Fig. 1 and embodying the novel type butt contact structure and mounting forming the invention;

Fig. 3 is an elevational view of the section illustrated in Fig. 2;

Fig. 4 is an exploded perspective view of the contact structure of Figs. 2, 3 and 5;

Fig. 5 is a fragmentary detail of the contact mounting of Figs. 2 and 3;

Fig. 6 is a section view taken along lines 5-5 of Fig. 5.

Referring to the drawings, main switch contacts and electromagnetic operating mechanism therefor are housed within a, cylindrical sectional casing, built up from molded insulating discs 60, I02, I08, H2, H2, l3ll and a metal shell 34, all of which are ultimately supported from a base plate 39 by means of the mounting plates 3i and 32 bolted on said base plate and extending at right angles to the face thereof. The immediate support for the casing sections is four spaced parallel rods 36, 31, 38, 39 running between and supported by mounting plates 3i, 32, and running through holes formed in each of the parts that make up the casing.

Although the casing comprises a number of sections or units, A, B, C, D, E and F as disclosed in my copending application Serial No.

511,855, the present invention is only concerned with the contact structure and mounting therefor in the sections C, D and E, which may be identical or substantially $0.

One suitable type of operating means is the electromagnet disclosed in my copending application Serial No. 511,855, but the invention is not limited to use with such operating means. If such operating means is used, the movable contact structure, forming the subject of the present invention, and the movable portion of the magnetic operating mechanism may be mounted on the main shaft 40 whose axis is the main axis of the device, and may have its ends journalled in and supported by the mounting plates 3| and 32. An insulating sleeve M is provided to insulate the shaft from all the parts it carries.

One or more of contactor sections C, D or E may be used. Since they may be identical or substantially so, description of one will suffice. The housing or base for each section may com- .prise a spacing disc I08 and a mounting disc I02,

molded from insulating material and suitably recessed and apertured for the fixed contacts, the movable contact structure and the main shaft.

The fixed contact members may be identical in structure and comprise stamped sheet metal pieces I of irregular shape, as indicated in Fig. 2, mounted upon the mounting disc I02 by means of screw bolts. The members I00 have a flat central portion lying in a radial recess adjacent the periphery of the disc I02. A portion I00a of the members I00 extends radially inward into a circular recess molded into the face of the disc, within which recess the movable contact member I04 may oscillate. edge of the inwardly-extending portions of the members I00 are rectangular contact blocks I00c of good contact material, such as silver, positioned so as to be engaged and disengaged by similar contact blocks I04c on the end of the arms I04b of the movable contact. The fixed members I00 may have an outwardly-extending terminal portlon I00b which may be twisted at right angles to the central portion of the members I00.

The rotatable contact member I04 comprises a stamped sheet metal member I04a having a, large central portion with a pair of counterbalancing arms I04b extending in diametrically opposite directions. To the ends of the arms I041) the contact tips I040 are permanently afllxed.

For the purpose of maintaining the circuit in case of momentary disengagement of contact blocks I04c and I000, dual supplementary contact members I06 stamped from sheet metal and lying against opposite faces of the central member I040. may be provided. Arcuate fingers I06a conforming substantially to the curvature of a radius about the axis of the movable contact may be provided on opposite sides of the main central portion in diametrically opposite positions so as to engage and disengage the inwardly-extending end I000. of the fixed contact members I00.

In order that these circuit maintaining supplementary contacts I06 shall engage their stationary counterparts after the butt-contact tips I040 engage the stationary contact blocks I000 and disengage before the contacts I04c separate from contacts I000, the center I04a of the contact member I04 is provided with four equally-spaced, concentrically-placed, arcuate key hole slots I04s, through each of which passes one of four pins I 057) that join the pair of supplementary contacts I06 by means of peened-over ends of said pins. The enlargement of the ends of the slots I04s around the pins I061; provides limited relative motion between the pins and the contact I04 to take care of manufacturing inaccuracies and to insure proper contact engagement. Lying in said slots I04s and pressing at one end against one end of the slot and at the other end against the pins I06p are small coiled compression springs I01, the springs being held in said slots by the adjacentlylying surfaces of the mid-portion of the contact Welded transversely onto one springs I01.

members I06. The supplementary contacts I00 and the main contacts I04 are so dimensioned that, in the disengaged or open-circuit condition, the angular distance between supplementary contacts N01; and I00a. is greater than the angular distance between the butt contacts I000 and N40. Thus the butt contacts will engage first.

Against the outside surfaces of the supplementary contact members I00 metal anchor members or driving discs I09. are placed; and all of these parts are then secured together to form a permanent dynamically and statically balanced unit. A square aperture is formed in each of the parts (except the member I04a which has a large circular aperture) for the reception of the main shaft 40 of the device, so that the movable contact unit will move with the main shaft as it oscillates. By reason of the large circular aperture in member I04a through which the shaft passes freely, the member I04a turns with the shaft only insofar as connections of the member I04a through the pins I081) and spring II" to the members I06 and I09 compel. There is thus provided a resilient lost-motion connection between the 'member I04a, its associated parts and the main shaft, which provides for self-adjustment of the member I04a to the fixed contacts.

Since the supplementary contacts I06 turn with the shaft 40 by reason of ,the non-circular connection with the shaft .40, the supplementary contacts will be positively moved to disengage the fixed contact members and will do so while the butt contacts I040 are still maintained in engagement with contacts I000 by the action of the Since the butt contacts I04c will engage first and disengage last, the supplementary contacts will normally only be called on to maintain the circuit in case of any tendency of the butt contacts to separate. The described structure, thus, maintains continuously the closed-circuit relation of the fixed and movable contact structures, considered as a whole, by reason of the. engagement of contacts I00a and I00a, so long as the shaft 40 remains unmoved, even though vibration or other causes might tend naomentarily to separate the butt contacts I04c, I 00.

When the spacing disc I08 and the mounting disc I02 are placed face to face with their recesses adjacent, the movable current carrying parts are enclosed and are insulated from the parts within the sections B and D.

From the foregoing it will be understood that the movable contact structure which I have in-.

vented can adjust itself to irregularities in the location and form of the fixed contacts due to manufacturing variations and inaccuracies; and when the contacts are engaged the contact pressure will be constant andflrm. Also the circuit will-be maintained in spite of possible momentary separation of the butt contacts due to shock or vi bration; but the danger of such momentary separation is minimized by the contacts form, as is also the amount of energy required to operate and maintain the contacts in engagement.

Modifications within the scope of my invention will occur to those skilled in the art. Therefore I do not, limit the invention to the embodiment disclosed.

I claim:

1. In a rotary switch, a rotary shaft, 8. contact unit mounted thereon comprising a rigid contact member having a centrally apertured portion and a contact carrying arm extending radially, said shaft extending freely through said central aperture and having limited rotary motion relative to said, rigid member, an anchor member slidably mounted on said shaft but always turning therewith, spring means acting on said rigid contact member and on said anchor member and biasing said contact member but permittin it limited movement relative to said anchor member, and fixed contact means engageable by said movable contact member.

2. In a rotary switch, a rotar shaft, a contact unit mounted thereon comprising a rigid contact member having a centrally apertured portion and a contact carrying arm extending radially, said shaft extending freely through said central'aperture and having limited rotary motion relative to said rigid member, an anchor member slidably mounted on said shaft but always turning therewith, and means loosely holding said rigid contact member and anchor member together, spring means acting on said rigid contact member and on said anchor member and biasing said contact member but permitting it limited movement relative to said anchor member, and fixed contact means engageable by said movable contact member.

3. In a rotary switch, a rotary shaft, a contact unit mounted thereon comprising a rigid contact member havin a centrally apertured portion and a contact carrying arm extending radially, said shaft extending freely through said central aperture and having limited rotary motion relative to said rigid member, a resilient contact member beside said rigid contact member slidably mounted on said shaft but always turning therewith, spring means biasing said rigid contact member and said resilient contact member but permitting relative movement between them. and fixed contact means engageable by said movable contact member.

4. In a rotary switch, a rotary shaft, a contact unit mounted thereon comprising rigid contact member having a centrally apertured portion and a contact carrying arm extending radially, said shaft extending freely through said central aperture and having limited rotary motion relative to said rigid member, a resilient contact member beside said rigid contact member slidably mounted on said shaft but always turning therewith, means holding said rigid and resilient contact members together, spring means biasing said rigid contact member and said resilient contact member but permitting relative movement between them, and fixed contact means engageable by said movable contact member.

5. In a rotary switch, a rotary shaft, a contact unit mounted thereon comprising a bridging butttype contact member having a centrally apertured portion through which said shaft extends freely and from which contact carrying arms extend radially, said shaft having limited rotary motion relative to said bridging member, ananchor member slidably mounted on said shaft but always turning therewith, spring means acting on said bridging member and on said anchor member, and biasing said bridging member but permitting it limited movement relative to said anchor memher, and fixed contact means engageable by said movable contact member.

6. In a rotary switch, a rotary shaft, a contact unit mounted thereon comprising a bridging butttype contact member having a centrally apertured portion through which said shaft extends motion relative to said bridging member, said bridging member being recessed for the reception of spring means, anchor members on opposite sides of said bridging member slidably mounted on said shaft but always turning therewith, spring means retained in the recesses of said bridging member by said anchor members and acting on both said members but permitting limited movement relative to said anchor member, and fixed contact means engageable by said bridging contact members.

7. In a rotary switch, a rotary shaft, a contact unit mounted thereon comprising a bridging butttype contact member having a centrally apertured portion through which said shaft extends freely and from which contact carrying arms extend radially, said shaft having limited rotary motion relative to said bridging member, resilient contact means lying beside said bridging memher and slidably mounted on the shaft but always turning therewith, spring means exerting a biasing effect on said bridging member and said resilient, contact means and permittin limited relative movement of said members, and fixed contact means engageable by said bridging contact member.

8. In a rotary switch, a rotary shaft, a contact unit mounted thereon comprising a bridging butttype contact member having a centrally apertured portion through which said shaft extends freely and from which contact carrying arms extend radially, said shaft having limited rotary motion relative to said bridging member, resilient contact means lying beside said bridging member and slidably mounted on the shaft but always turning therewith, spring means exerting a biasing effect on said bridging member and said resilient contact means and permitting limited relative movement of said members, an anchor means, and means holding said resilient contact means and said bridging member and anchor means together as a unit.

9. In a rotary switch, a rotary shaft, a contact unit mounted thereon comprising a bridging butt,- ty e contact .member having a centrally apertured portionthrough which said shaft extends freely and from which contact carrying arms extend radially, said shaft having limited rotary motion relative to said bridging member, an anchor member slidably mounted on said shaft but always turning therewith, spring means acting on said bridging member and on said anchor member, and biasing said bridging member but permitting it limited movement relative to said anchor member, and fixed contact means engageable by said movable contact member, each of the parts which comprise said unit being so constructed and arranged as to be statically and dynamically balanced and forming in combination with the other partsthereof a dynamically and statically balanced unit.

10. In a rotary switch, a rotary shaft, a contact unit mounted thereon comprising a bridging butttype contact member having a centrally apertured portion through which said shaft extends freel and from which contact carrying arms extend radially, said shaft having limited rotary motion relative to said bridging member, said bridging member being recessed for the reception of spring means, anchor members on opposite sides of said bridging member slidably mounted on said shaft but always turning therewith, spring means retained in the recesses of said bridging member by said anchor members and acting on both said members but permitting limited movement relative to said anchor member, and fixed contact means engageable by said 7 bridging contact members, each of the parts which comprise said unit being so constructed and arranged as to be statically and dynamically balanced and forming in combination with the other parts thereof a dynamically and statically balanced unit.

11. In a rotary switch, a rotary shaft, a contact unit mounted thereon comprising a bridging butttype contact member having a centrally apertured portion through which said shaft extends freely and from which contact carrying arms extend radially, said shaft having limited rotary motion relative to said bridging member, resilient contact means lying beside said bridging memher and slidably mounted on the shaft but always turning therewith, spring means exerting a biasing effect on 'said bridging member and said resilient contact means and permitting limited relative movement of said members, and fixed contact means engageable by said bridging contact member, each of the parts which comprise said unit being so constructed and arranged as to be statically and dynamically balanced and forming in combination with the other parts thereof a dynamically and statically balanced unit.

12. In a rotary switch, a rotary shaf t, a contact unit mounted thereon comprisin'g a bridging butttype contact member having a centrally apertured portion through which said shaft extends freely and from which contact carrying arms extend radially, said shaft havin limited rotary motion relative to said bridging member, resilient contact means lying beside said bridging memher and slidably mounted on the shaft but always turning therewith, spring means exerting a biasing effect on said bridging member and said resilient contact means and permitting limited relative movement of said members, an anchor means, and means holding said resilient contact means and said bridging member and anchor means together as a unit, each of the parts which comprise said unit being so constructed and arranged as to be statically and dynamically balanced and forming in combination with the other parts thereof a dynamically and statically balanced unit.

13. In a rotary switch, a rotary shaft, a contact unit mounted thereon comprising a bridging butttype contact member having a centrally apertured portion through which said shaft extends freely and from which contact carrying arms extend radially, said shaft 'having limited rotary motion relative to said bridging member, an anchor member slidably mounted on said shaft but always turning therewith, spring means acting on said bridging member and on said,anchor member, and biasing said bridging member but permitting it limited movement relative to""said anchor member, and fixed contact means engageable by said movable contact member, the parts of said unit being constructed and arranged to form, in combination, a statically and dynamically balanced unit.

14. In a rotary switch, a rotary shaft, a contact unit mounted thereon comprising a bridging butttype contact member having a centrally apertured portion through which said shaft extends freely and from which contact carrying arms extend radially, resilient contact means lying beside said bridging member and "slidably mounted on the shaft and turning therewith, spring means exerting a biasing effect on said bridging memher and said resilient contact means and permitting limited relative movement of said members, and fixed contact means engageable by said bridging contact member, the angular distance between said resilient contact means and the fixed contact means complementary thereto being greater than the angular distance between the bridging contact member and its complementar fixed contact means, to cause said bridging contact member to close first and open last.

15. In a rotary switch, a rotary shaft, a contact unit mounted thereon comprising a bridging butttype contact member having a centrally apertured portion through which said shaft extends freely and from which contact carrying arms ex- "the shaft and turningtherewith, spring means exerting a biasing effect on said bridging member and said resilient contact means and permitting limited relative movement of said members, anchor means, and means holding said resilient contact means and said bridging member and anchor means together as a unit, the angular distance between said resilient contact means and the fixed contact means complementary thereto being greater than the angular distance between the bridging contact member and its complementary fixed contact means, to cause said bridging contact member to close first and open last. 1 16. In an electric switch, a rotary shaft, a contact unit mounted thereon comprising a bridging butt-type contact member having a centrally apertured portion through which said shaft loose- 1y passes, anchor members slidably mounted on said shaft and turning with the shaft, said central portion having a plurality of arcuate recesses with enlarged end portions, pins passing through said enlarged portions and holding said anchor members and bridging member together, said pins having limited motion with said enlarged end portions to permit self-adjustment of said bridging contact member, spring means in said recesses acting on said pins and affording contact pressure in switch-closed condition, and fixed butt contact means engageable by said bridging contact member.

HAROLD E. SCHLEICHER.

REFERENCES CITED UNITED STATES PATENTS Name Date Harrington Mar. 16, 1915 Number 

